From de39657404b87c918dc230ed1af401e3133551cc Mon Sep 17 00:00:00 2001
From: pranavchoudhary-tech <pranav.nstblr@gmail.com>
Date: Tue, 18 Aug 2026 12:24:51 +0530
Subject: [PATCH 1/2] gh-155976: Refresh COLORS and COLOR_PAIRS in
 update_lines_cols

---
 Lib/test/test_curses.py | 36 ++++++++++++++++++++++++++++++++++++
 Modules/_cursesmodule.c | 26 ++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
index f582336fae17344..f494c0fbf9d567e 100644
--- a/Lib/test/test_curses.py
+++ b/Lib/test/test_curses.py
@@ -3047,6 +3047,42 @@ def test_set_term(self):
         self.assertIs(curses.set_term(a), b)  # returns the previous one
         self.assertIs(curses.set_term(b), a)
 
+    def test_set_term_refreshes_lines_cols_colors(self):
+        s1 = self.make_pty()
+        s2 = self.make_pty()
+        a = curses.newterm('xterm', s1, s1)
+        if hasattr(curses, 'start_color'):
+            try:
+                curses.start_color()
+            except curses.error:
+                pass
+        b = curses.newterm('xterm-256color', s2, s2)
+        if hasattr(curses, 'start_color'):
+            try:
+                curses.start_color()
+            except curses.error:
+                pass
+
+        curses.set_term(a)
+        lines_a, cols_a = curses.LINES, curses.COLS
+        colors_a = getattr(curses, 'COLORS', None)
+
+        curses.set_term(b)
+        lines_b, cols_b = curses.LINES, curses.COLS
+        colors_b = getattr(curses, 'COLORS', None)
+
+        self.assertEqual(curses.set_term(a), b)
+        self.assertEqual(curses.LINES, lines_a)
+        self.assertEqual(curses.COLS, cols_a)
+        if colors_a is not None:
+            self.assertEqual(curses.COLORS, colors_a)
+
+        self.assertEqual(curses.set_term(b), a)
+        self.assertEqual(curses.LINES, lines_b)
+        self.assertEqual(curses.COLS, cols_b)
+        if colors_b is not None:
+            self.assertEqual(curses.COLORS, colors_b)
+
     def test_window_keeps_screen_alive(self):
         # The standard window keeps its screen alive; dropping every other
         # reference and collecting must not invalidate the window.
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 006e27d55d8925d..da0e46e44131586 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -7557,6 +7557,32 @@ update_lines_cols(PyObject *private_module)
         goto error;
     }
     Py_DECREF(o);
+
+    if (curses_start_color_called) {
+        o = PyLong_FromUnsignedLongLong((unsigned long long)COLORS);
+        if (o == NULL) {
+            goto error;
+        }
+        if (PyDict_SetItemString(exposed_module_dict, "COLORS", o) < 0) {
+            goto error;
+        }
+        if (PyDict_SetItemString(private_module_dict, "COLORS", o) < 0) {
+            goto error;
+        }
+        Py_DECREF(o);
+
+        o = PyLong_FromUnsignedLongLong((unsigned long long)COLOR_PAIRS);
+        if (o == NULL) {
+            goto error;
+        }
+        if (PyDict_SetItemString(exposed_module_dict, "COLOR_PAIRS", o) < 0) {
+            goto error;
+        }
+        if (PyDict_SetItemString(private_module_dict, "COLOR_PAIRS", o) < 0) {
+            goto error;
+        }
+        Py_DECREF(o);
+    }
     Py_DECREF(exposed_module);
     return 1;
 

From 71719c036f87478e0a21aaf681b114c719d1b31d Mon Sep 17 00:00:00 2001
From: pranavchoudhary-tech <pranav.nstblr@gmail.com>
Date: Tue, 18 Aug 2026 14:08:08 +0530
Subject: [PATCH 2/2] gh-155976: Add news entry

---
 .../next/C_API/2026-08-18-12-30-00.gh-issue-155976.xyz123.rst    | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/C_API/2026-08-18-12-30-00.gh-issue-155976.xyz123.rst

diff --git a/Misc/NEWS.d/next/C_API/2026-08-18-12-30-00.gh-issue-155976.xyz123.rst b/Misc/NEWS.d/next/C_API/2026-08-18-12-30-00.gh-issue-155976.xyz123.rst
new file mode 100644
index 000000000000000..4395f8c1503f1fc
--- /dev/null
+++ b/Misc/NEWS.d/next/C_API/2026-08-18-12-30-00.gh-issue-155976.xyz123.rst
@@ -0,0 +1 @@
+Fix an issue where :func:`curses.set_term` did not update :const:`curses.COLORS` and :const:`curses.COLOR_PAIRS` when switching terminal screens.